At this advanced stage of the development of the computer art commercially available chips provide systems capable of many types of functional operations and full alphameric data processing capabilities.
The keyboard computer input art has been developed to interface with computer systems. Thus, for example, U.S. Pat. No. 3,892,958 - C. C. Tung provides a multiple key keyboard with means for changing the mode of computer operation to adapt the keyboard to three different sets of functions, all illustrated on keyboard indicia and with the three modes and corresponding key functions differentiated by indicia of three different colors, such as black, orange and blue.
Also other techniques are known in the prior art for producing more functions per key in a keyboard assembly in an attempt to interface with more of the computer functions by a keyboard of modest size. Exemplary are: U.S. Pat. No. 4,042,777 - F. C. Bequaert et al., Aug. 16, 1977 which permits chords of several simultaneously actuated keys to supplement individual keystrokes and thus expand the communication interface capabilities of a keyboard with a computer. German Publication No. DE 2924515 - S. Pretzsch published Jan. 15, 1981 provides for selection of more than one of several adjacent keys simultaneously by a single fingerstroke to increase the number of selections on a keyboard; and U.S. Pat. No. 4,344,069 - E. S. Prame, Aug. 10, 1982 provides a single handed keyboard with alphanumeric capabilities by selecting a sequence of keystrokes for alpha characters.
However, none of these keyboards are operable to enter comprehensive data and instructions in a computer in the touch mode similar to that of touch typewriters, where data may be entered quickly and accurately by a typist with little effort or explicit choice decisions after becoming acquainted with the keyboard layout. In particular, it is not feasible in the prior art to use a keyboard of so few keys that it can be operated by a single hand to enter a comprehensive set of different data and instructions, for example a hundred and fifty different selectable choices that provides full alphanumeric data operation as well as full computer control and access. Furthermore, there have not been significant developments in the art, other than the above-mentioned U.S. Pat. No. 4,042,777, that relate to the interface of a one hand operated keyboard and a computer in such a way that touch typing can proceed. There have been no known such keyboard systems developed with the particular objects of one-handed computer entry with rapidity and elimination of the source of errors from such manual actions as hitting a wrong key, hitting extra keys, resting the fingers on a wrong set position or counting a sequence of numbered key actuations for an entry. No particular attention has been given to operator finger fatigue or avoidance of unnatural finger positions and reach.
It is therefore an objective of this invention to improve the state of the art by resolving some of these problems and providing improved keyboard systems not heretofore available in the art. Other objects, features and advantages of the invention will be found throughout the following description, the drawings and the claims.